如何检查设备中是否安装了摄像头？

Question

这是我的代码。我想从相机或图库中选择图像。 为此，我必须检查设备的相机支持功能。

  public void selectImage() {
            final String[] items = new String[]{"Camera", "Gallery"};
            final Integer[] icons = new Integer[]{R.drawable.ic_camera, R.drawable.ic_gallery};
            ListAdapter adapter = new ArrayAdapterWithIcon(getActivity(), items, icons);
            new AlertDialog.Builder(getActivity()).setTitle("Select Picture")
                    .setAdapter(adapter, new DialogInterface.OnClickListener() {
                        public void onClick(DialogInterface dialog, int item) {
                            if (items[item].equals("Camera")) {
                                if (//here i want to check is there mobile exists camera or not) {
                                    Intent intent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
                                    startActivityForResult(intent, REQUEST_CAMERA);
                                } 
                            } else if (items[item].equals("Gallery")) {

                                    Intent intent = new Intent();
                                    intent.setType("image/*");
                                    intent.setAction(Intent.ACTION_GET_CONTENT);
                                    intent.addCategory(Intent.CATEGORY_OPENABLE);
                                    startActivityForResult(Intent.createChooser(intent, "Select Picture"), PICK_IMAGE);

                            }
                        }
                    }).show();

        }

我尝试了很多，但没有成功。

Answer 1

import android.hardware.Camera;`

使用Camera.getNumberOfCameras();。如果它返回值大于0，则表示您的设备有摄像头。

Answer 2

使用它来显示图库以从中选择图像：

private void showGallery() {
    Intent intent = new Intent();
    intent.setType("image/*");
    intent.setAction(Intent.ACTION_GET_CONTENT);
    intent.addCategory(Intent.CATEGORY_OPENABLE);
    startActivityForResult(intent, 1234);
}

---

使用它打开相机（检查设备是否有相机）：

private void showCamera() {
        // get the package manager and check if device has camera
        PackageManager pm = getPackageManager();
        if (pm.hasSystemFeature(PackageManager.FEATURE_CAMERA)) {
            Intent takePictureIntent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);

            // ensure that there is some activity to handle camera intents
            if (takePictureIntent.resolveActivity(pm) != null) {
                startActivityForResult(takePictureIntent, 5678);
            }
        } else {
            Snackbar.make(mView, "your device dont have camera", Snackbar.LENGTH_LONG).show();
        }
    }

注意：确保在清单中声明相机的权限为：

<manifest ... >
    <uses-feature android:name="android.hardware.camera"
                  android:required="true" />
    ...
</manifest>

更多详情，请查看this。